Update!
https://logfaqs.com/lfaqslink_1-0.user.js
This version adds Yeah! counts to posts/topics on the Topic and Post pages, similar to how they appear on this site without the button to actually add/remove a Yeah! since that requires being logged in here - but with the easy to use links to LogFAQs pages it's a simple enough task to pop in and do it anyways.
Think I'm done for now, until I come across any problems myself with this script.